The present invention relates generally to the field of motor control circuitry and more specifically to controlling both the speed and direction of a number of DC motors. More particularly the general purpose of the ambulator control circuitry disclosed herein is to produce the signals necessary to control motors which propel a mobile platform for a standing paraplegic. The direction in which the platform moves can be controlled by manipulating a 3-axis joy stick controller.
At present there are no other known devices which raise a paraplegic into a standing position and allow him to move about on a minimum size platform that is under power. Motorized wheelchairs and similar devices have been disclosed for providing greater automobility for the invalid occupant whereby he can achieve independence from the need for a pushing assistant and increase his traveling range by both increasing the speed of travel and eliminating the muscle strain and fatigue of self-propulsion by means of the drive wheels of the chair. These systems are entirely inadequate for the paraplegic since they generally provide no mechanism for raising him to a standing position nor do they permit him mobility in the standing position. Moreover, it has been customary in the past to use transistors in their linear region to control the motors of the wheelchair or similar device. Operation of transistors in this mode is inherently less efficient than the pulse width modulated signal approach disclosed herein.